Method of filling cooling holes in an airfoil component

Abstract

In an aspect, a method of filling a plurality of cooling holes in an airfoil component, the method comprises injecting a curable composition into a fill channel such that the curable composition flows through the fill channel to the plurality of cooling holes; forming a plurality of beads of the curable composition on a surface of the component over the plurality of cooling holes; directing a radiation to the respective beads in directions parallel to the respective central axes of the cooling holes associated with the respective beads to cure curable composition of the respective beads; and heating the component to cure the curable composition located in the fill channel.

what is claimed is: 
     
         1 . A curable composition for filling cooling holes in an airfoil, the composition comprising:
 a urethane (meth)acrylate oligomer;   a reactive diluent;   a photoinitiator;   an optional thickening agent; or   an optional additive other than the thickening agent.   
     
     
         2 . The curable composition of  claim 1 , wherein the urethane (meth)acrylate oligomer is present in an amount of 15 to 85 weight percent, percent based on a total weight of the curable composition. 
     
     
         3 . The curable composition of  claim 2 , wherein the urethane (meth)acrylate oligomer is present in an amount of 30 to 70 weight percent, percent based on a total weight of the curable composition. 
     
     
         4 . The curable composition of  claim 1 , wherein the reactive diluent is present in an amount of 20 to 60 weight percent, based on a total weight of the curable composition. 
     
     
         5 . The curable composition of  claim 1 , wherein the reactive diluent is present in an amount of 20 to 50 weight percent, based on a total weight of the curable composition. 
     
     
         6 . The curable composition of  claim 1 , wherein the reactive diluent comprises a substituted vinyl monomer with one or more functional groups. 
     
     
       7. The curable composition of  claim 1 , wherein the reactive diluent comprises 2-hydroxyethyl (meth)acrylate, isobornyl (meth)acrylate, n-vinyl caprolactam, n,n-dimethyl acrylamide, or mixtures thereof. 
     
     
         8 . The curable composition of  claim 1 , wherein the photoinitiator comprises free radical photoinitiators; wherein the free radical photoinitiators include Norrish Type I and Type II photoinitiators. 
     
     
         9 . The curable composition of  claim 1 , wherein the free radical photoinitiators are present in an amount of 1 to 10 weight percent, based on a total weight of the curable composition. 
     
     
         10 . The curable composition of  claim 1 , wherein the free radical photoinitiators are present in an amount of 2 to 7 weight percent, based on a total weight of the curable composition. 
     
     
         11 . The curable composition of  claim 8 , wherein the Norrish Type I free radical photoinitiators include homolytic free-radical photoinitiators; wherein the homolytic free-radical photoinitiators include benzoin derivatives, methylolbenzoin or 4-benzoyl-1,3-dioxolane derivatives, benzilketals, α,α-dialkoxyacetophenones, α-hydroxy alkylphenones, α-aminoalkylphenones, acylphosphine oxides, bisacylphosphine oxides, acylphosphine sulphides, halogenated acetophenone derivatives, or a combination thereof. 
     
     
         12 . The curable composition of  claim 8 , wherein the Norrish Type II free radical photoinitiators include hydrogen abstraction photoinitiators; wherein the hydrogen abstraction photoinitiators comprise aromatic ketones. 
     
     
         13 . The curable composition of  claim 11 , wherein the hydrogen abstraction photoinitiators comprise benzophenone, xanthone, derivatives of benzophenone, blends of benzophenone and benzophenone derivatives, Michler's Ketone, ethyl Michler's Ketone, thioxanthone or other xanthone derivatives or a combination thereof. 
     
     
         14 . The curable composition of  claim 1 , wherein the thickening agent is present in an amount of 2 to 10 weight percent, based on a total weight of the curable composition. 
     
     
         15 . The curable composition of  claim 13 , wherein the thickening agent is present in an amount of 2 to 6 weight percent, based on a total weight of the curable composition. 
     
     
         16 . The curable composition of  claim 1 , wherein the thickening agent comprises a thixotrope. 
     
     
         17 . The curable composition of  claim 15 , wherein the thixotrope comprises untreated fumed silica, a surface modified fumed silica, a polyamide thixatrope or a mixed mineral thixotrope. 
     
     
         18 . The curable composition of  claim 1 , wherein the additive comprises at least one of a heat stabilizer, an ultraviolet light stabilizer, a free-radical scavenger, a colorant, a surfactant, a plasticizer, or an opacity-modifying agent. 
     
     
         19 . The curable composition of  claim 1 , wherein the curable composition is activated by ultraviolet (UV) radiation, visible light radiation, infrared radiation, electron beam radiation or by heat.